Clamp for paper-cutting machines



Mmh 31,1953 WQRUPP 2,633,195

CLAMP FOR PAPER-CUTTING MACHI NES Filed Nov. 16, 1948 3 Sheets-Sheet lINVENTOR.

WILLIAM C.RUPP

ATTORA/EYS.

March 31, 1953 w c, P 2,633,195

CLAMP FOR PAPER-CUTTING MACHINES Filed Nov. 16, 1948 3 Sheets-Sheet 2r-g 1 L INVENTOR. WILL/AM C.PUPP

ATTOBIVE Y6.

March 31, 1953 w. c. RUPP 2,6336195 CLAMP FOR PAPER-CUTTING MACHINESFiled Nov. 16, 1948 3 Sheets-Sheet 3 INVENTOR. WILLIAM C. RUPP BY-viATTORNCXS Patented Mar. 31, 1953 CLAMP FOR PAPER-CUTTING MACHINESWilliam G. Rupp, Parma, Ohio, assignor to The Chandler & Price Company,Cleveland, Ohio,

a corporation of Ohio Application November 16, 1948, Serial No. 60,341

This invention relates, as indicated, to a clamp for a paper cuttingmachine and, more particularly, to power-operated hold-down or binderclamp means of novel construction.

Paper cutting machines of the type with which this invention isconcerned may be of the gen- 'eral form illustrated and described inTyler et a1.

Patent No. 1,967,600 and Reichert et al. Patent No. 2,305,735, forexample. In such machines a fly-wheel driven by an electric motor may beconnected through clutch means with a crank adaptedv to reciprocate theknife to cut a stack of sheets. It. is necessary to clamp such stacktightly until the out has been completed and the knife withdrawn, and ahand-wheel operated screw clamp is commonly provided for such purpose.It is also known to operate such clamp through mechanism including thesame clutch adapted to reciprocate the knife so that both clamp and,knife will be power operated in synchronism.

A primary object of my invention is to provide a power-operated binderclamp which will be much more rapid and efficient in operation than thecommon hand clamp means.

A further object is to provide for automaticactuation of such clamp intimed relation to actuation of the knife, while at the same timepermitting power operation of either the clamp or knife individually,when desired.

Another object is to provide a power-operated papercutting machine ofless costly construction than any known in the prior art but which willhave the novel advantages indicated above.

Other objects of my invention will appear as the description proceeds.

' ticularly pointed out in the claims, the following description and theannexed drawing setting forth in detail certain illustrative embodimentsof theinvention, these'being indicative, however, of but a few of thevarious ways in which the principle of the invention maybe employed.

In said annexed drawing:

Fig. 1 is a frontelevational. view of a paper cutting machine embodyingmy invention, partly broken away to show certain elements of internalconstruction;

Fig. 2 is a vertical sectional view taken along the line 2-2 on Fig. 1;I

Fig. 3 is a wiring diagram showing the arrangement of theelectriccontrol means; and

-. Fig. 4 is-a rear elevational view of the" drive 7 Claims. (01.164-51) mechanism of the machine showing one wellknown form of clutchand drive means for the cutter.

Referring now more particularly to said drawing and especially Fig. 1thereof, there is there illustrated a paper cutting machine whichembodies the novel features of my invention. As is conventional in suchmachines, a wide horizontal table I is mounted on a heavy cast frame 2adapted rigidly to support the same. An adjustable back gauge 3 whichmay be of the type disclosed in' Reichart Patent No. 2,203,547 isprovided together with a traveling steel tape 4 indicating the positionof such gauge. A knife 5 is secured by means of. screws 6 to a knife barI. which is mounted for vertical reciprocation in upper frame fl. Awooden knife stick 9 is inset in the upper surface of table I to avoidpossible damage to the-knife.

The knife bar '1' and knife 5 are adapted thus to be reciprocated inconventional manner by means of a connecting rod l0, crank II andcrankshaft l2 driven through a clutch from a flywheel t2 driven by anelectric motor 49. Such clutch is adapted to be operated through aclutch lever it which may be of a dual motion safety type such as thatrequiring the same to be first movedto the right and then to the left tocause engagement of such clutch to reciprocate the knife bar.- When onecycle of operation has been completed, the clutch will be automaticallykicked out and the knife left in elevated position.

Back gauge 3 may be shifted back and forth as desired by means ofhand-wheel Liand locked in adjusted position by locking. lever it. Allof the above-described mechanism is conventional in various papercutting machines now on the market.

Referring now more particularly to Fig. 2 of the drawing, I provide avertically reciprocable binder clamp shoe it carried by a screw llthreadably engaging nut it in such shoe which is located directly behindknife 5. As shown in Figs; 1 and 2, this shoe normally projectsslightlydownwardly below the edge of knife 5 when shoe and knife are in elevatedposition. Screw I! is driven by a reversible electric torque motor I 9through a speed reducer 29 carried by upper frame 8. Such motor is of atype which may be temporarily stalled without damage thereto.

Referring now to Fig. 3 of the drawing, two

parallel electric circuits are provided including relays 2i and 22respectively operative to open and close corresponding contacts 21' and22 for such motor L9; to reverse: the. same; Operation of relay 2| willcause screw I! to be driven in a direction to elevate binder clamp l6and operation of relay 22 is eifective to cause rotation of screw I1 tolower such clamp.

The crank H which operates to reciprocate connecting rod l6 and therebythe knife 5, is driven by an electric motor 40 through V-belts 4i,flywheel 42, drive shaft 43, and worm and gear unit 44. The flywheelunit includes a clutch 45 adapted to be actuated through shifting ofcone 46 releasably to engage flywheel 42 with shaft 46. Shifter cone 4!is likewise operative to apply brake 48 to stop rotation of shaft 43simultaneously with disengagement of clutch 45. Such cones 46 and 41 areadapted thus to be reciprocated by means of clutch lever l3 and yoke 49pivotally mounted at 5!]. As previously indicated, conventionalmechanism will ordinarily also be provided to ensure single-cycleoperation, the clutch bein disengaged and the brake appliedautomatically after the knife has been reciprocated to make the cut andreturned to elevated position. The particular drive means thus employedto operate the knife forms no part of the present invention.

Now considering Figs. 1 and 3 together, the remainder of the mechanismwill be described in conjunction with an explanation of the operationthereof. A selector switch 23 may be turned to select either Hand orAutomatic operation. When turned to Hand, switches 23A and 2313 will beopen. The binder clamp l6 may now be'raised or lowered independently ofknife bar I by pressing switch buttons 24 and 25 respectively. Whenswitch 25 is thus manually held closed, current will pass throughnormally closed switch 26 and relay 22 causing motor I9 to be operatedto move clamp l6 downwardly. Upon pressing switch 24, current will nowflow through normally closed switch 21 and relay 2| to cause motor [9 tooperate in the reverse direction to elevate such clamp. When the clampreaches fully elevated position as shown in Fig. 2, it will engage suchlimit switch 21 to open the same, thereby stopping the motor (sinceswitches 23B and 25 are both open).

Now turning selector 23 to Automatic, switches 23A and 23B are bothclosed. After the stack of sheets 28 has been properly arranged on table1 against back gauge 3, the operator then moves clutch lever l3 first tothe right and then to the left to cause engagement of clutch androtation of crankshaft l2. The preliminary movement of lever l3 to theright operated limit switch 29 completing the circuit through switch23B, switch 26, and relay 22 to initiate downward movement of the binderclamp 16. It will be seen, therefore, that such clamp starts itsdownward movement before the clutch is engaged to rotate crankshaft I2and crank H to reciprocate the knife. This means that the stack ofsheets 28 will always be firmly clamped by the binder clamp shoe beforethe knife engages the same. As above explained, the motor I9 merelystalls for the brief period (about one second) which is required for theknife to make the cut and return. A cam 30 is mounted on shaft I2 toturn therewith and is positioned to engage and operate switch 26 justprior to completion of upward reciprocation of the knife after makingthe cut. Engagement of cam 36 with normally closed switch 26 causes thelatter to open and simultaneously closes normally open contacts 26A.Opening of switch 26 de-energizes relay 22 as well as holding circuit29', permitting switch-29 to reopen. Closing of.

contacts 26A completes the circuit through switch 23A, normally closedswitch 21 and relay 2| with the result that motor I9 is now reversed toelevate the binder clamp l6. Such binder clamp is therefore not raisedfrom the stack 28 until after the knife 5 is clear thereof. As thebinder clamp nears completion of its upward movement, it engages limitswitch 21 and opens the same, thereby breaking the circuit and stoppingmotor I9. Such interruption of the circuit likewise breaks holdingcircuit 26A, permitting switch 26A to reopen and switch 26 to close.Since, as above described, the knife operating clutch is automaticallykicked out after completion of one cycle and the clutch handle [3automatically returned to initial position, the entire mechanism is nowset up and ready for another operating cycle.

Motor I!) may be provided with a manual control 32 of well-known type ofregulating the clamping pressure by means of a variable resistance inthe motor circuit. Or an adjustable friction clutch may be provided, ifdesired.

It will be seen from the foregoing that I have provided an automaticpaper cutting machine which is exceedingly flexible in operation,permitting the knife and clamp to be reciprocated independently of eachother when desired. I have found that my new machine may be operated ata rate of forty cuts per minute which is consid erably faster than theoperator is able to load the same.

The electrical interconnection of the controls ensures that positiveclamping pressure will be maintained on the stack from a moment beforethe knife begins the out until after the knife is withdrawn. The entiredevice is substantially foolproof and the work produced is of uniformlyhigh quality even when employing relatively unskilled operators.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. Ina power-operated paper cutting machine having a knife, crank meansadapted to reciprocate such knife, and a clutch-operating leveroperative to connect such crank with drive means therefor; areciprocable clamp adapted to clamp the work during such cuttingoperation, screw means threadedly engaging said clamp to thusreciprocate the same, a reversible electric torque motor mounted todrive said screw means, a switch adapted to be actuated by suchclutch-operating lever when the latter is shifted to initiatereciprocation of such knife, actuation of such switch completing thecircuit of said motor to drive said screw means to advance said clamp, acam rotatable with such knife-reciprocating crank means, switch meanspositioned to be actuated by said cam after rotation of such crank toreciprocate such knife to make the cut and return such knife from thecut, actuation of said last-named switch means interrupting such motorcircuit and completing the motor circuit effective to reverse thedirection of rotation of said screw means and thereby retract saidclamp, and a limit switch engageable by said clamp in retracted positionto stop said motor.

2. In a paper cutting machine having a table adapted to support a stackof sheets thereon, a.

vertically. reciprocableclamp. adapted to clamp such stack on suchtable, and a knife operative to out such stack thus clamped; meansoperative to raise and lower such clamp comprising a vertically disposedscrew mounted against axial movement and threadedly engaging such clamp,a reversible electric torque motor mounted to drive said screw to raiseand lower such clamp, switch means automatically operable to energizesaid motor to lower such clamp in advance of downward cutting movementof such knife, switch means automatically operative after completion ofsuch cut and withdrawal of such knife to reverse said motor to raisesuch clamp, and a limit switch engageable by such clamp in elevatedposition operative to stop said motor.

3. In a paper cutting machine having a table adapted to support a stackof sheets thereon, a vertically reciprocable clamp adapted to clamp suchstack on such table, and a knife operative to out such stack thusclamped; means operative to raise and lower such clamp comprising areversible electric torque motor, means driven by said motor engagingsuch clamp operative to raise and lower the latter as determined bycontrol means to energize said motor to lower Q such clamp in advance ofsuch knife, switch means automatically operative after completion ofsuch cut and withdrawal of such knife to reverse said motor to raisesuch clamp, and switch means operative to stop said motor upon return ofsuch clamp to elevated position.

4. In a paper cutting machine having a table adapted to support a stackof sheets thereon, a vertically reciprocable clamp adapted to clamp suchstack on such table, and a knife operative to out such stack thusclamped; means opera tive to raise and lower such clamp comprising areversible electric torque motor operative when driven in one directionto lower such clamp and when driven in the other direction to raise thesame, control means operative to initiate reciprocation of such knife,means responsive to operation of said control means adapted to energizesaid motor to lower such clamp in advance of such knife, means operativeafter return of such knife from the cut to reverse said motor to elevatesuch clamp, and means adapted automatically to stop said motor uponreturn of such clamp to elevated position.

5. In a paper cutting machine having a clamp reciprocable into and outof clamping position, a knife operative to out such stack thus clamped;means operative to reciprocate such clamp comprising a reversibleelectric torque motor, drive means connected with said motor and clampadapted to be driven by said motor and operative when driven in onedirection to move such clamp into clamping position and when driven inthe other direction to move such clamp into unclamped position, controlmeans operative to actuate said motor to drive such clamp to clamp thework and to reverse said motor to drive such clamp to unclamp the work,and means automatically operative to time such actuation of said motorin relation to movement of such knife to clamp the work prior toengagement of such knife with the work and to unclamp the work onlyafter such knife has returned from the cut.

6. In a paper cutting machine having a table adapted to support a stackof sheets thereon, a vertically reciprocable clamp adapted to clamp suchstack on such table, and a knife operative to out such stack thusclamped; means operative to raise and lower such clamp comprisingreversible clamp drive means, a stallable electric torque motor adaptedto operate said drive means, control means adapted to energize saidmotor to lower such clamp, said motor being adapted to stall withoutharm thereto during a short clamping period, whereby such stack may beactively clamped during performance of the cutting operation, controlmeans automatically operative to reverse said motor to raise such clampafter completion of such cutting operation, and control meansautomatically operative to lie-energize said motor when such clamp hasbeen fully raised thereby.

7. In a paper cutting machine having a table adapted to support a stackof sheets thereon, a vertically reciprocable clamp adapted to clamp suchstack on such table, a knife mounted to out such stack thus clamped, andseparate drive means for such clamp and knife; drive means for suchclamp comprising a reversible, stallable electric torque motor, screwmeans engaging such clamp and adapted to be driven by said motor toraise and lower such clamp, control means adapted to energize said motorto lower such clamp, said motor being adapted to stall without harmthereto during a short clamping period whereby such stack may be firmlyand actively clamped during performance of the cutting operation,control means actuated by such knife drive means automatically operativeto reverse said motor to raise such clamp after completion of suchcutting operation and withdrawal of such knife from the cut, and controlmeans automatically operative to de-energize said motor when such clamphas been fully raised thereby.

WILLIAM C. RUPP.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,729,582 Kast Sept. 24, 19292,230,802 Klein Feb. 4, 1941

